Commit f3fe97f6 authored by Brett Creeley's avatar Brett Creeley Committed by Tony Nguyen
Browse files

ice: Fix MSI-X vector fallback logic 



The current MSI-X enablement logic tries to enable best-case MSI-X
vectors and if that fails we only support a bare-minimum set. This
includes a single MSI-X for 1 Tx and 1 Rx queue and a single MSI-X
for the OICR interrupt. Unfortunately, the driver fails to load when we
don't get as many MSI-X as requested for a couple reasons.

First, the code to allocate MSI-X in the driver tries to allocate
num_online_cpus() MSI-X for LAN traffic without caring about the number
of MSI-X actually enabled/requested from the kernel for LAN traffic.
So, when calling ice_get_res() for the PF VSI, it returns failure
because the number of available vectors is less than requested. Fix
this by not allowing the PF VSI to allocation  more than
pf->num_lan_msix MSI-X vectors and pf->num_lan_msix Rx/Tx queues.
Limiting the number of queues is done because we don't want more than
1 Tx/Rx queue per interrupt due to performance conerns.

Second, the driver assigns pf->num_lan_msix = 2, to account for LAN
traffic and the OICR. However, pf->num_lan_msix is only meant for LAN
MSI-X. This is causing a failure when the PF VSI tries to
allocate/reserve the minimum pf->num_lan_msix because the OICR MSI-X has
already been reserved, so there may not be enough MSI-X vectors left.
Fix this by setting pf->num_lan_msix = 1 for the failure case. Then the
ICE_MIN_MSIX accounts for the LAN MSI-X and the OICR MSI-X needed for
the failure case.

Update the related defines used in ice_ena_msix_range() to align with
the above behavior and remove the unused RDMA defines because RDMA is
currently not supported. Also, remove the now incorrect comment.

Fixes: 152b978a ("ice: Rework ice_ena_msix_range")
Signed-off-by: default avatarBrett Creeley <brett.creeley@intel.com>
Tested-by: default avatarTony Brelinski <tonyx.brelinski@intel.com>
Signed-off-by: default avatarTony Nguyen <anthony.l.nguyen@intel.com>
parent 943b881e

drivers/net/ethernet/intel/ice/ice.h

+3 −1
Original line number Diff line number Diff line
@@ -68,7 +68,9 @@ 
#define ICE_INT_NAME_STR_LEN	(IFNAMSIZ + 16)

#define ICE_AQ_LEN		64

#define ICE_MBXSQ_LEN		64

#define ICE_MIN_MSIX		2

#define ICE_MIN_LAN_TXRX_MSIX	1

#define ICE_MIN_LAN_OICR_MSIX	1

#define ICE_MIN_MSIX		(ICE_MIN_LAN_TXRX_MSIX + ICE_MIN_LAN_OICR_MSIX)

#define ICE_FDIR_MSIX		1

#define ICE_NO_VSI		0xffff

#define ICE_VSI_MAP_CONTIG	0

drivers/net/ethernet/intel/ice/ice_lib.c

+9 −5
Original line number Diff line number Diff line
@@ -161,8 +161,9 @@ static void ice_vsi_set_num_qs(struct ice_vsi *vsi, u16 vf_id) 


	switch (vsi->type) {

	case ICE_VSI_PF:

		vsi->alloc_txq = min_t(int, ice_get_avail_txq_count(pf),

				       num_online_cpus());

		vsi->alloc_txq = min3(pf->num_lan_msix,

				      ice_get_avail_txq_count(pf),

				      (u16)num_online_cpus());

		if (vsi->req_txq) {

			vsi->alloc_txq = vsi->req_txq;

			vsi->num_txq = vsi->req_txq;
@@ -174,8 +175,9 @@ static void ice_vsi_set_num_qs(struct ice_vsi *vsi, u16 vf_id) 
		if (!test_bit(ICE_FLAG_RSS_ENA, pf->flags)) {

			vsi->alloc_rxq = 1;

		} else {

			vsi->alloc_rxq = min_t(int, ice_get_avail_rxq_count(pf),

					       num_online_cpus());

			vsi->alloc_rxq = min3(pf->num_lan_msix,

					      ice_get_avail_rxq_count(pf),

					      (u16)num_online_cpus());

			if (vsi->req_rxq) {

				vsi->alloc_rxq = vsi->req_rxq;

				vsi->num_rxq = vsi->req_rxq;
@@ -184,7 +186,9 @@ static void ice_vsi_set_num_qs(struct ice_vsi *vsi, u16 vf_id) 


		pf->num_lan_rx = vsi->alloc_rxq;



		vsi->num_q_vectors = max_t(int, vsi->alloc_rxq, vsi->alloc_txq);

		vsi->num_q_vectors = min_t(int, pf->num_lan_msix,

					   max_t(int, vsi->alloc_rxq,

						 vsi->alloc_txq));

		break;

	case ICE_VSI_VF:

		vf = &pf->vf[vsi->vf_id];

drivers/net/ethernet/intel/ice/ice_main.c

+2 −6
Original line number Diff line number Diff line
@@ -3430,18 +3430,14 @@ static int ice_ena_msix_range(struct ice_pf *pf) 
	if (v_actual < v_budget) {

		dev_warn(dev, "not enough OS MSI-X vectors. requested = %d, obtained = %d\n",

			 v_budget, v_actual);

/* 2 vectors each for LAN and RDMA (traffic + OICR), one for flow director */

#define ICE_MIN_LAN_VECS 2

#define ICE_MIN_RDMA_VECS 2

#define ICE_MIN_VECS (ICE_MIN_LAN_VECS + ICE_MIN_RDMA_VECS + 1)



		if (v_actual < ICE_MIN_LAN_VECS) {

		if (v_actual < ICE_MIN_MSIX) {

			/* error if we can't get minimum vectors */

			pci_disable_msix(pf->pdev);

			err = -ERANGE;

			goto msix_err;

		} else {

			pf->num_lan_msix = ICE_MIN_LAN_VECS;

			pf->num_lan_msix = ICE_MIN_LAN_TXRX_MSIX;

		}

	}